205213535121 has 24 divisors (see below), whose sum is σ = 318773521440. Its totient is φ = 117086878272.

The previous prime is 205213535119. The next prime is 205213535159. The reversal of 205213535121 is 121535312502.

It is not a de Polignac number, because 205213535121 - 2¹ = 205213535119 is a prime.

It is a super-2 number, since 2×205213535121² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (205213535161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 962316 + ... + 1156061.

It is an arithmetic number, because the mean of its divisors is an integer number (13282230060).

Almost surely, 2^205213535121 is an apocalyptic number.

205213535121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

205213535121 is a deficient number, since it is larger than the sum of its proper divisors (113559986319).

205213535121 is a wasteful number, since it uses less digits than its factorization.

205213535121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2119053 (or 2119046 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

Adding to 205213535121 its reverse (121535312502), we get a palindrome (326748847623).

The spelling of 205213535121 in words is "two hundred five billion, two hundred thirteen million, five hundred thirty-five thousand, one hundred twenty-one".